Build Your Own Arcade Controls Forum

Main => Monitor/Video Forum => Topic started by: ZEN on June 08, 2009, 01:26:25 am

Title: WG 25K7195 (k7000) Color issues - no red
Post by: ZEN on June 08, 2009, 01:26:25 am

I serached forums for a while with no definitive answers so i pass on to you experts

I have a working W/G K700, specifically a 25K7195 monitor.  ArcadeVGA card working it, everything is great except little to no RED, this is after adjusting all the pots (also black levels on sister board).  I am not running a JPAC, and I have no video amplifier,  could this be the culprit?, I would not assume so since all else looks great, and Ultimarc noted WG monitors dont need amplified.

Does the standard CAP kit solve color issues?  I guess I never thought this was a reaosn to do caps, but since this is my first foray into Mame to arcade monitor I need to learn.  Any help would be great.

I dont think the breakout cable is bad, I have two K7000 monitors and the red level in that one, when hooked up showed up considerably more (that test was on a monitor that is not as crisp).

I am missing somthing probably obvious, any help I would appreciate.. :banghead:

Title: Re: WG 25K7195 (k7000) Color issues - no red
Post by: SirPeale on June 08, 2009, 07:10:33 am

The reason you don't find a definitive answer is because there isn't one.  There are several reasons for missing colors:

1) bad color drive transistor on the neckboard

2) bad input transistor on the chassis

3) bad input cable

4) broken color input on the chassis

5) failing tube and/or failing red electron gun in the neck of the tube.

I've highlighted that which I think it is, since it's a K7000.

If you can find access to someone with a rejuvenator, you can test your tube to see if that's indeed what it is.  And possibly repair the problem for the time being.

The color is there, right?  Just really dim?

Title: Re: WG 25K7195 (k7000) Color issues - no red
Post by: Ken Layton on June 08, 2009, 12:12:04 pm

Bad tube, especially if the tube was made by Zenith. Connecting it to a rejuvenator to test it will confirm if the tube is bad or not.

Title: Re: WG 25K7195 (k7000) Color issues - no red
Post by: ZEN on June 08, 2009, 03:39:18 pm

the color is there, but just rather dim, the red posts on the board really only change the spectrum and it reds up the backgriund a little.
-the tube is a Zenith, and it operates great except for the low red.
-I am about to buy a new 25" now I have this problem, do you guys reccomend I go a certain route for a decent price....

Title: Re: WG 25K7195 (k7000) Color issues - no red
Post by: SirPeale on June 08, 2009, 03:59:41 pm

A rejuvenator might be able to help the tube.  Only way to tell is to hook the tube up to it.  Post your location, perhaps a member is nearby that can help.

Other than that, tube swap.

Title: Re: WG 25K7195 (k7000) Color issues - no red
Post by: ZEN on June 08, 2009, 04:40:50 pm

I am located in the Lincoln/Omaha Nebraska area...any outside chance someone out there has one? 
-Not sure I could handle a tube swap or not, saw the examples of such on the web.  At this point, it may be best to buy a new monitor, what existin,g 25 is best bang for yer buck?
  I am on my 3rd 25", thus I am frustrated....

 I may try a cap kit on a 257131 that also works....


Thanks Ken and Peale for your help now and in the future

Title: Re: WG 25K7195 (k7000) Color issues - no red
Post by: qrz on June 08, 2009, 10:06:23 pm

ask around for the name of any former TV repairmen.

most of us still have a lot of ....... er , stuff  ;)

and yes , zenith did have some crappy crts mid 90's .    mostly grid shorts (that are easy to circumvent )

trash day is a good time to locate a donor crt . assuming a rejuve doesn't do the trick .

qrz